Unable to start the OS after instal

I’m new to Zorin and Linux.
I’ve downloaded the Zorin OS Lite and have installed it for several times which went well. The OS is working fine (although the trackpad stopped working).
Yet every time that remove the USD stick and try to run the computer I’m getting the error “No boot device found”. This means that can only run the OS with the usb in.
I’ve tried all the installation options available but every single one of them gives the same head ache.

Can anyone help?

This sounds like the system installed grub on your USB instead of on your system hard drive.
Does your computer use an SSD, NVMe or eMMC?